What is jaundice?

Jaundice is not a disease but rather a sign that can occur in many different diseases. Jaundice is the yellowish staining of the skin and sclerae (the whites of the eyes) that is caused by high levels in blood of the chemical bilirubin. The color of the skin and sclerae vary depending on the level of bilirubin. When the bilirubin level is mildly elevated, they are yellowish. When the bilirubin level is high, they tend to be brown.

What causes jaundice?

Bilirubin comes from red blood cells. When red blood cells get old, they are destroyed. Hemoglobin, the iron-containing chemical in red blood cells that carries oxygen, is released from the destroyed red blood cells after the iron it contains is removed. The chemical that remains in the blood after the iron is removed becomes bilirubin.

The liver has many functions. One of the liver's functions is to produce and secrete bile into the intestines to help digest dietary fat. Another is to remove toxic chemicals or waste products from the blood, and bilirubin is a waste product. The liver removes bilirubin from the blood. After the bilirubin has entered the liver cells, the cells conjugate (attaching other chemicals, primarily glucuronic acid) to the bilirubin, and then secrete the bilirubin/glucuronic acid complex into bile. The complex that is secreted in bile is called conjugated bilirubin. The conjugated bilirubin is eliminated in the feces. (Bilirubin is what gives feces its brown color.) Conjugated bilirubin is distinguished from the bilirubin that is released from the red blood cells and not yet removed from the blood which is termed unconjugated bilirubin.

Jaundice occurs when there is 1) too much bilirubin being produced for the liver to remove from the blood. (For example, patients with hemolytic anemia have an abnormally rapid rate of destruction of their red blood cells that releases large amounts of bilirubin into the blood), 2) a defect in the liver that prevents bilirubin from being removed from the blood, converted to bilirubin/glucuronic acid (conjugated) or secreted in bile, or 3) blockage of the bile ducts that decreases the flow of bile and bilirubin from the liver into the intestines. (For example, the bile ducts can be blocked by cancers, gallstones, or inflammation of the bile ducts). The decreased conjugation, secretion, or flow of bile that can result in jaundice is referred to as cholestasis: however, cholestasis does not always result in jaundice.

What problems does jaundice cause?

Jaundice or cholestasis, by themselves, causes few problems (except in the newborn, and jaundice in the newborn is different than most other types of jaundice, as discussed later.) Jaundice can turn the skin and sclerae yellow. In addition, stool can become light in color, even clay-colored because of the absence of bilirubin that normally gives stool its brown color. The urine may turn dark or brownish in color. This occurs when the bilirubin that is building up in the blood begins to be excreted from the body in the urine. Just as in feces, the bilirubin turns the urine brown.

Besides the cosmetic issues of looking yellow and having dark urine and light stools, the symptom that is

associated most frequently associated with jaundice or cholestasis is itching, medically known as pruritus. The itching associated with jaundice and cholestasis can sometimes be so severe that it causes patients to scratch their skin "raw," have trouble sleeping, and, rarely, even to commit suicide.

It is the disease causing the jaundice that causes most problems associated with jaundice. Specifically, if the jaundice is due to liver disease, the patient may have symptoms or signs of liver disease or cirrhosis. (Cirrhosis represents advanced liver disease.) The symptoms and signs of liver disease and cirrhosis include fatigue, swelling of the ankles, muscle wasting, ascites (fluid accumulation in the abdominal cavity), mental confusion or coma, and bleeding into the intestines.

If the jaundice is caused by blockage of the bile ducts, no bile enters the intestine. Bile is necessary for digesting fat in the intestine and releasing vitamins from within it so that the vitamins can be absorbed into the body. Therefore, blockage of the flow of bile can lead to deficiencies of certain vitamins. For example, there may be a deficiency of vitamin K that prevents proteins that are needed for normal clotting of blood to be made by the liver, and, as a result, uncontrolled bleeding may occur.

What diseases cause jaundice?

Increased production of bilirubin

There are several uncommon conditions that give rise to over-production of bilirubin. The bilirubin in the blood in these conditions usually is only mildly elevated, and the resultant jaundice usually is mild and difficult to detect. These conditions include: 1) rapid destruction of red blood cells (referred to as hemolysis), 2) a defect in the formation of red blood cells that leads to the over-production of hemoglobin in the bone marrow (called ineffective erythropoiesis), or 3) absorption of large amounts of hemoglobin when there has been much bleeding into tissues (e.g., from hematomas, collections of blood in the tissues).

Acute inflammation of the liver

Any condition in which the liver becomes inflamed can reduce the ability of the liver to conjugate (attach glucuronic acid to) and secrete bilirubin. Common examples include acute viral hepatitis, alcoholic hepatitis, and Tylenol-induced liver toxicity.

Chronic liver diseases

Chronic inflammation of the liver can lead to scarring and cirrhosis, and can ultimately result in jaundice. Common examples include chronic hepatitis B and C, alcoholic liver disease with cirrhosis, and autoimmune hepatitis.

Infiltrative diseases of the liver

Infiltrative diseases of the liver refer to diseases in which the liver is filled with cells or substances that don't belong there. The most common example would be metastatic cancer to the liver, usually from cancers within the abdomen. Uncommon causes include a few diseases in which substances accumulate within the liver cells, for example, iron (hemochromatosis), alpha-one antitrypsin (alpha-one antitrypsin deficiency), and copper (Wilson's disease).

Inflammation of the bile ducts

Diseases causing inflammation of the bile ducts, for example, primary biliary cirrhosis or sclerosing cholangitis and some drugs, can stop the flow of bile and elimination of bilirubin and lead to jaundice.

Blockage of the bile ducts

The most common causes of blockage of the bile ducts are gallstones and pancreatic cancer. Less common causes include cancers of the liver and bile ducts.

Drugs

Many drugs can cause jaundice and/or cholestasis. Some drugs can cause liver inflammation (hepatitis) similar to viral hepatitis. Other drugs can cause inflammation of the bile ducts,